The purpose of this invention is to provide oxygen enriched air to an internal combustion engine (IC). The automobile industry in the United States has had to cater to the consumer by supplying vehicles that provide driveability. Driveability is defined as autos with motors with sufficient torque and horsepower to allow good acceleration when needed to start from a dead stop or to quickly enter traffic on the highway. In general, consumers outside the United States have, mostly due to the higher cost of fuel, been willing to accept lighter weight vehicles with poor acceleration performance. Thus, the average United States automobile has an engine with higher horsepower rating, along with the higher displacement needed to satisfy the consumers demand. These engines are usually less efficient and provide a higher volume of tailpipe gasses due to the higher displacement of these engines. It is well know that nitrous oxide can be injected into the intake manifold of an engine along with additional fuel to provide a tremendous power surge for automobiles. The nitrous oxide which is approximately 36% oxygen by weight to 64% nitrogen provides the additional oxygen needed to combust the additional fuel. This reaction increases the torque and power of the engine by a significant amount (typically 75–200 horse power or more). The use of nitrous oxide for this purpose puts a tremendous strain on the engine, thereby reducing its life. Because of such strain, typically the nitrous oxide fuel mixture is used for only about 10 seconds at a time as longer periods of use could damage the engine.
The present invention, in some modes of operation or demands on the engine, does not require the use of additional fuel but rather provides more oxygen to assure that the normally supplied amount of fuel is more efficiently used to gain additional value (horse power) from that fuel. Under the present invention, there is a reduction in the amount of unburned hydrocarbons and nitrogen compounds supplied to the exhaust pipe. The present invention not only increases the amount of oxygen in the combustion reaction, it also reduces the amount of nitrogen in this reaction, thereby providing efficiency of operation while reducing pollutants. Any excess oxygen in the combustion reaction will burn some of the hydrocarbons in the exhaust system. The present invention may be used with gasoline, propane, natural gas, diesel, and hydrogen fueled internal combustion engines. If additional fuel is also supplied to the engine while using oxygen enriched air, additional power can be achieved. The additional fuel would be less than that supplied in the case where nitrous oxide is used as that level of power improvement cannot be maintained for extended periods of time. The present invention can supply an increase in power output which is sustainable over long periods of time and, under controlled conditions, for the life of the vehicle.
It is also well known that a process known as Pressure Swing Absorption (PSA) can be used to increase the level of oxygen and reduce the level of nitrogen in an air stream. The prior art process utilizes a molecular sieve, that absorbs nitrogen from air when the air is placed in contact with it under pressure. When air is passed through the molecular sieve contained in a bed or container at above atmospheric pressure, most of the nitrogen is absorbed into the bed with the result that the air stream flowing from the bed has a higher percent of oxygen than normal air. When the molecular sieve in such bed has reached its saturation point of absorbing nitrogen, the air at above atmospheric pressure is directed to a second molecular sieve bed to continue the absorbing process. The first bed is then exposed to atmospheric pressure, with the result that the nitrogen in that bed is desorbed. The higher than atmospheric pressure air flow is alternated between the two beds resulting in a continuous flow of oxygen enriched air. The foregoing type of system has not been used in internal combustion engines so far as the applicant can determine.
The object of the present invention is to introduce small increases in oxygen enrichment to the fuel propelling an internal combustion engine. Large quantities of air are introduced to an internal combustion engine during operation. For example, a 200 cu inch displacement engine running at 2000 RPM at a speed of 60 miles/hr requires approximately 120 cu ft. of air/minute. The 120 cu. ft. of air contains approximately 24 cu. ft. of oxygen. To boost the power at that operative point by 10%, 2½ cu. ft. of oxygen enriched air would be needed to be added to the 120 cu. ft. of combustion air along with an appropriate amount of fuel. In that mode of operation, the power boost could be used to pass traffic.
The apparatus of the present invention has the capability of providing oxygen enriched air in those quantities without damaging the engine.
Under one embodiment, the present invention provides an on-board oxygen generation system which, under appropriate system control, results in the desired engine improvement. The oxygen enriched air is stored in a container and is selectively released into the manifold along with additional fuel. The oxygen enriched air produced and delivered to the engine intake manifold reduces overall emission while boasting torque resulting in higher horsepower to the drive train.
Under another embodiment of the present invention, oxygen enriched air may be fed directly from the molecular sieve O2 enrichment chamber to the combustion chamber.
The automobile industry has recognized that smaller, higher output engines are desirable and have developed and provided to the market systems (Superchargers, Turbochargers) which do allow smaller motors to develop higher torque and horsepower. A supercharger is a belt driven compressor which supplies pressurized air to the engine intake manifold. A turbocharger uses a turbine located in the exhaust system to power a turbine in the intake system which pressurizes the intake manifold. Both systems pressurize the combustion air supplied to the engine cylinders. The designs of these systems are based on the fact that additional power output requires additional air and fuel to be supplied to the combustion chamber. This result is achieved by pressurizing the air in the intake manifold and injecting more fuel. The net result of pressurizing the intake manifold is that additional oxygen is forced into the combustion chamber when the intake valve is opened. Along with the additional oxygen that enters the combustion chamber, the approximate 80% of the air which is made up of nitrogen is also pressurized into the combustion chamber. This high level of nitrogen in effect goes along for the ride and exits the tailpipe. As a result of boosting the output of the engine using such systems, the volume of gases exiting the tailpipe to atmosphere increases over that resulting from the displacement of the same normally aspirated engine. The present invention in its preferred form does not increase pressure to the intake manifold. As a result, the volume of the tailpipe gasses is directly related to the displacement of the engine, and is not increased by any pressurizing of air to the manifold.
However, the present invention does not rule out the use of a supercharger or turbocharger. In those cases when it is desired to gain the maximum horsepower output from an engine, the oxygen enriched air could be supplied as a portion of the air being pressurized by the supercharger or turbocharger. This would result in additional oxygen in the air to fuel ratio in the combustion chamber and would develop additional horsepower output on supercharged or turbocharged engines. This invention also describes a system where all the combustion air is treated in a supercharged or turbocharged engine to boost power.
The objective of using a smaller motor in automobiles, while still providing driveability, has also been approached by the auto industry in the hybrid gas/electrical design. In this system a smaller horsepower engine (gas or diesel) is used to charge a set of batteries. The vehicle is then driven by electrical motors with the energy being supplied by the batteries. One hybrid system uses a gasoline engine which has a horsepower rating greater than is needed to maintain cruising speed but not large enough to provide good acceleration. The energy stored in the batteries provides the desired acceleration and the lower energy demand during cruising. This hybrid system is presently being offered to the consumer.
For the hybrid system to be fully acceptable and find widespread use in the industry a good deal of new technology must be production hardened. New reliable drive systems, improved battery life and lower costs are some of the many challenges that need to be overcome.
This invention, in effect, follows a similar strategy. That is during cruising, the low energy demand is provided by the internal combustion engine while O2 enriched air is manufactured and placed in a storage tank. That O2 enriched air is later provided to the engine with additional fuel to boost torque and horsepower when demanded during acceleration. The difference is that with this invention, standard automotive drive components that have been developed to a high level of reliability are used. The potential energy in the form of O2 enriched air is stored in a light weight low cost storage container. In contrast, the hybrid gas/electric system must haul around heavy, high cost batteries which are expensive to replace. It is projected by many in the industry that such hybrid system will take many years to become accepted and will require the industry to make huge capital investments in new production systems.
Drag racers have long recognized that the addition of oxygen to the combustion chamber results in very large increases in output torque and horsepower of the engine. However, prior to the present invention a practical system that could be used on board the vehicle to continuously separate nitrogen from oxygen was not available. Drag racers for years have used the nitrous oxide system (NOS) in a high pressure tank to supply oxygen to their engines to develop significant torque and horsepower increases. Improvements of from 1 to 3 full seconds and 10 to 15 mph in a quarter mile (0.25 mile) can be expected. Holley Inc. (www.HOLLEY.com) supplies systems which can be bolted on most production engines. For example this company supplies 50 state legal nitrous oxide systems for 4.0 L Mustang and 305/350 GM V8's. Although these systems are very effective in boosting engine torque and horsepower the system is not practical and cost effective for the average driver who wants driveability, good mileage and a low polluting vehicle. The system requires a high pressure cylinder of nitrous oxide to be hooked up to the engine. This high pressure cylinder must be changed after approximately three minutes of high output use.
The lesson from the nitrous oxide system (NOS) is that increases of oxygen levels in the combustion chamber can make tremendous engine output improvements and that, at the proper level of oxygen addition, stock engines can retain the reliability desired. The Holly website states that if maximum reliability from most stock engines is desired, a limit must be placed on the amount of boost that is achieved. The site states that “4 cylinder engines normally allow an extra 40–60 horsepower, 6 cylinder engines usually work great between 75–100 horsepower, smaller block V8's (302/350/400 cid) can typically accept up to an extra 140 horsepower and big block (427 to 454 cid) might accept from 125–200 extra horsepower.” The term “cid” is cu. inch displacement.
When using the NOS system the nitrous oxide is injected into the intake manifold together with additional fuel. This nitrous oxide gas mixes with the normally aspirated air and fuel from the fuel injectors to provide the final mix in the combustion chamber. At about 572 degrees F., the nitrous oxide gas breaks down and releases oxygen (36 percent by weight) and nitrogen. This 36 percent oxygen mixes with the regular aspirated air containing 20 percent oxygen. As a result, the oxygen level supplied to the combustion chamber, is somewhere in between these two values. The full 36 percent level of oxygen would shorten the life of the engine. The correct level of oxygen boost to assure long engine life should be determined by testing.
Presently modern automobile engines are computer controlled by the Engine Control Unit (ECU). The ECU is supplied data from sensors which measure:
Oxygen in the exhaust system
Mass air flow
Throttle position
Coolant temperature
Voltage
Manifold absolute pressure
Engine speed
This data together with the performance chips in the ECU is used to calculate the control actions needed under various operating conditions and send appropriate control signals. One of these control signals (pulse width) is sent to the fuel injection system to vary the amount of fuel provided at various driving conditions. The mass air flow, throttle position and rate of change of the throttle sensors could be used to control the addition of O2 enriched air and additional fuel as contemplated by the present invention to optimize the power output of the engine. Thus optimizing of the engine in all modes of operation would be available.
During a cold start of the engine the pollution level at the exhaust pipe is high as the combustion reaction is taking place at low temperature. By using the present invention during this mode, the ECU would supply additional O2 enriched air to the combustion chamber to raise the reaction temperature and speed the heat-up of the engine. This would reduce the pollution level during that period. During cruising if the oxygen level in the exhaust system drops to a low level additional oxygen would be introduced into the intake manifold (or exhaust manifold) to assure sufficient oxygen is available to complete combustion.